Terminal for aluminum wire

ABSTRACT

An electrical terminal for use with aluminum wire and having tines for gripping the wire insulation, and inwardly extending cutting edges for penetrating the insulation to contact the wire core.

United States Patent Inventor Appl. No.

Filed Patented Assignee Priority Kama] Ahmed Stanmorc, England 37,643

May 15, 1970 Jan. 4, 1972 A.M.P. Incorporated Harrisburg, Pa. May 30, 1970 Great Britain TERMINAL FOR ALUMINUM WIRE 2 Claims, 4 Drawing Figs.

US. Cl

Int. Cl Field of Search seed Primary Examiner-Joseph H. McGlynn Attorneys-Curtis, Morris and Safford, William J. Keating,

William Hintze, Frederick W. Rating, John R. Hopkins, Adrian J. La Rue and Jay L. Seitchik ABSTRACT: An electrical terminal for use with aluminum wire and having tines for gripping the wire insulation, and inwardly extending cutting edges for penetrating the insulation to contact the wire core.

- PATENTED JAN 4 I972 2 l/l/l TERMINAL FOR ALUMINUM WIRE This invention relates to a terminal for aluminum wire and to a connection comprising such a terminal crimped to aluminum wire.

Aluminum and its alloys tend to form an insulating oxide coating and have a low mechanical strength. Stripping an insulating sheath from an aluminum conductor requires considerable skill if the aluminum is not to be nicked; such skill is at a premium. Nicking or otherwise marring the aluminum core is especially bad in the case of low-current single-strand wire because the mechanical strength is affected.

SUMMARY A terminal according to this invention comprises a barrel portion and a contact portion, tines directed inwardly of the barrel portion adjacent one end adapted mechanically to grip an insulated electrical wire having an aluminum core receiva ble in the barrel, at least two inwardly extending cutting edges spaced apart longitudinally and extending transversely of the barrel portion between the tines and the contact portion adapted to penetrate the insulation and electrically contact the aluminum core on crimping the terminal and the wire.

This invention is described, by way of example, with reference to the accompanying drawing, in which:

FIG. 1 is a plan view of a blank for making a terminal;

FIG. 2 is a longitudinal median sectional view of a terminal made from the blank of FIG. 1;

FIG. 3 is an end view of another terminal; and

FIG. 4 is a partial longitudinal sectional view of the terminal of FIG. 3 crimped to aluminum wire.

The blank of FIG. 1 is a flat brass-stamping having a generally oblong portion 1, the precursor of the barrel portion, and a ring-tongue contact portion 2, these portions being joined by an integral neck portion 3. Two rows of tines 4 are formed from the oblong portion at a location remote from the contact portion 2, conveniently by punching holes and using the upstanding burrs as the tines 4. Two generally sigmoidshaped cuts 5, arranged back-to-back, are made between the neck 3 and the tines 4 generally parallel to each other and the shorter side of the oblong portion 1. The opposed outer walls of the cuts 5 are raised generally normal to the oblong portion 1 to form cutting edges 6 which are then inclined slightly apart to the condition shown in FIG. 2. The longer edges of the oblong portion 1 are then rolled towards each other to direct the tines 4 and the cutting edges 6 inwardly of the barrel portion so formed.

An end portion of an aluminum wire, not shown, is passed into the barrel portion 1 forwardly of the tines 4, the free end of the wire stopping adjacent the neck portion 3. The assembly so made is then crimped, so forcing the wire onto the cutting edges 6 which penetrate through the wire insulation electrically to contact the aluminum core. The cutting edges 6 are spaced apart sufficiently to ensure that, on crimping, the

portion of wire between them is held sufficiently taut for the edges to penetrate the insulation and contact the core. The crimping also causes the tines 4 to grip but not penetrate the wire to prevent rearward axial withdrawal of the wire from the terminal. Optionally, the neck 3 may be folded up to form a flap to protect the free end of the wire, coated with inhibitor.

The two cutting edges 7 of the terminal of FIG. 3 are bifurcated longitudinally of the barrel portion to define a wirereceiving gap 8, and the floor between them is cut away, FIG. 4. The tines 4 are the same as those of the terminal of FIGS. 1 and 2, and the contact portion comprises an end extension having a bent-up portion 9 terminating in a tab receptacle 10 standing above the level of the barrel portion 1 and at an acute angle to the major axis of the barrel portion. The barrel portion has an outer insulating sheath 13, FIG. 4. The terminal of FIG. 3 is crimped to a wire comprising a sheath II about an aluminum core 12, to the condition shown in FIG. 4 where the two cutting edges 7 are bent apart by the crimping and the walls of each gap 8 cut through the insulating sheath 11 to contact the core I2. I

The contact portion may be of taper pm form for use in junction boxes. The insulation may be of natural or synthetic resin, and is preferably polyethylene. The number of cutting edges may be increased, dependent on the current density of the wire to be terminated.

The invention is of special value in terminating telephone wires having polyethylene sheathed single strand aluminum cores, each of which carries a current of about 1 l milliamps at 50 volts DC.

What is claimed is:

1. An electrical terminal for aluminum wire, comprising a barrel portion and a contact portion, tines directed inwardly of the barrel portion adjacent one end adapted mechanically to grip an insulated wire having an aluminum core receivable in the barrel, at least two inwardly extending cutting edges spaced apart longitudinally and extending transversely of the barrel portion between the tines and the contact portion adapted to penetrate the insulation electrically to contact the aluminum core on crimping the terminal and the wire, the cutting edges being inclined apart longitudinally of the barrel portion.

2. An electrical terminal for insulating aluminum wire, including a wire-receiving portion, tines directed inwardly of the wire-receiving portion adjacent one end thereof, the tines being adapted mechanically to grip an insulated wire having an aluminum core receivable in the wire-receiving portion, at least two inwardly extending cutting edges spaced apart longitudinally and extending transversely of the wire-receiving portion to penetrate the insulation electrically to contact the aluminum core on crimping, the cutting edges being formed from the floor of the wire-receiving portion and being inclined apart longitudinally of the wire-receiving portion.

and the neck may be 1 $3253? 1 TED STATES PATENT @EHCIE @E'HMQATE m CE'MN January 4, 19 72 Pacenf No 3 6 3 3 1 5 3 Dated Invention-(s) KAMAL AHMED It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Claim 2, line 1, column 2, "insulating" should be insulated Signed and sealed this 2nd day of May B972,

(SEAL) i ittsskfiz EDWARD ZF'ZJLEICHER, JR. ROBERT GOTTSGHALK Y Commissioner" of Patents Attssting Officer AMP 2684 

1. An electrical terminal for aluminum wire, comprising a barrel portion and a contact portion, tines directed inwardly of the barrel portion adjacent one end adapted mechanically to grip an insulated wire having an aluminum core receivable in the barrel, at least two inwardly extending cutting edges spaced apart longitudinally and extending transversely of the barrel portion between the tines and the contact portion adapted to penetrate the insulation electrically to contact the aluminum core on crimping the terminal and the wire, the cutting edges being inclined apart longitudinally of the barrel portion.
 2. An electrical terminal for installed aluminum wire, including a wire-receiving portion, tines directed inwardly of the wire-receiving portion adjacent one end thereof, the tines being adapted mechanically to grip an insulated wire having an aluminum core receivable in the wire-receiving portion, at least two inwardly extending cutting edges spaced apart longitudinally and extending transversely of the wire-receiving portion to penetrate the insulation electrically to contact the aluminum core on crimping, the cutting edges being formed from the floor of the wire-receiving portion and being inclined apart longitudinally of the wire-receiving portion. 